Film with oxygen absorbing regions

ABSTRACT

A packaging material includes an oxygen scavenger material dispersed in bands in a polymer sheet.

FIELD OF THE INVENTION

This invention relates to a packaging material that includes an oxygenscavenger material dispersed in bands in a polymer sheet. In particularit is directed to such a polymer sheet utilized in forming packages.

BACKGROUND OF THE INVENTION

Flexible packaging sheeting is known to be utilized to form bags andstandup pouches and is broadly used in the medical, food packaging andfood service industries. Conventional bags and pouches used in foodpackaging usually contain barrier resins and are cosmetically decorated.Materials for making these containers can be polyolefins, polystyrene,nylon, polyester, and biopolymers such as polylactic acid. The structureof these materials usually is multilayer and may include an oxygenbarrier material such as polyethylene vinyl alcohol (EVOH), polyethyleneterephthalate, polyvinylidene chloride (PVDC), and nylon. The bags aredesigned to maintain freshness of the food or medicine in the bag. Acommon way to improve the freshness of a meat package is to put oxygenabsorber in a sachet in the meat package (U.S. Publication No.2011-0217430-Chau). It is desirable to avoid the use of sachets in manyloose food products as they may become ingested or broken after thepackage is opened. It is known to put oxygen absorber on an adhesivelabel that is on the inside of a package.

While the techniques of utilizing an inner label for oxygen absorptionor a sachet are reasonably effective they have the disadvantage thatthey are relatively high cost as each requires an extra step in forminga package and additionally another material formation process to makethe label or sachet. There is need for a package that does not requirethe additional step of providing oxygen absorber into the package formedof polymer sheet, but also provides a package that has large areas oftransparent polymer so that the end-user can see the material in thepackage.

DESCRIPTION OF RELATED ART

It is shown in U.S. Publication No. 2011/0217430-Chau that oxygenscavenger may be placed into a foam sheet for use in packaging meat.

U.S. Pat. No. 5,820,956-Hatakeyama discloses a multilayer structuralmaterial including an oxygen absorber that may be utilized in formingpackaged goods.

U.S. Publication No. 2010/0255231-Chau discloses an oxygen scavengingfilm assumed for use in making bags or pouches.

U.S. Pat. No. 5,045,264-Kirksey discloses a method and apparatus formaking extruded plastic polymer film with strips embedded therein of asecond thermoplastic material.

U.S. Pat. No. 5,687,863-Cullen and U.S. Pat. No. 5,686,161-Cullen et al.disclose a label containing oxygen scavenger which may be placed on theinside of a package.

Problem to be Solved by the Invention

There is a need for an oxygen absorbing package that may be formedutilizing known package-making apparatus and processes without extrasteps for providing the oxygen absorption. There also is a need for anoxygen absorbing packaging sheet that will enable the making of apackage having transparent viewing areas.

BRIEF SUMMARY OF THE INVENTION

The invention relates to a packaging material which includes acontinuous polymer sheet wherein said sheet includes at least onelongitudinal band of oxygen absorber.

In another embodiment of the invention a package utilizing a portion ofthe continuous polymer sheet with a band of oxygen absorber is formed.

Advantageous Effect of the Invention

The invention provides a package with oxygen absorbing areas andtransparent areas that may be made from one sheet of film by ordinarypackaging forming methods which involve folding a sheet to form apackage and sealing the edges of the folded materials together.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a top view of a portion of a continuous sheet having theoxygen absorbing bands of the invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 in oneembodiment of the invention.

FIG. 2A is a cross-sectional view taken along line 2-2 according toanother embodiment of the invention.

FIG. 3 is a top view of the sheet of FIG. 1 having printing over theoxygen absorbing bands.

FIG. 4 is a view of a package formed from a portion of the sheet of FIG.3.

FIG. 5 is a view of a different package formed from a portion of thesheet of FIG. 3.

FIG. 6 is a view of a package, having a transparent window, formed inaccordance with the invention.

FIG. 7 is an elevation view of an extrusion head suitable for creating afilm according to one aspect of the invention.

FIG. 7A is a plan view of a film made using the extrusion head of FIG.7.

FIG. 8 is an elevation view of an extrusion head suitable for creating afilm according to one aspect of the invention.

FIG. 8A is a plan view of a film made using the extrusion head of FIG.8.

FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 7A.

FIG. 10 is an elevation view of an extrusion head suitable for creatinga film according to one aspect of the invention.

FIG. 11 is an elevation view of an extrusion head suitable for creatinga film according to one aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention has numerous advantages over prior processes andproducts. The invention provides a continuous strip of materialcontaining longitudinal bands of oxygen absorber between and separatedby transparent areas. The continuous strip may be utilized inconventional bag and pouch making machines to form a pouch or bag thathas oxygen absorbent properties but still allows transparent areas forviewing of a product in the pouch or bag. Present processes to formoxygen absorbent pouches and bags require a separate step to place asachet into the bag or a label onto the bag to provide oxygen absorbentproperties. Previous materials with oxygen absorbers throughout thelateral width of a sheet could be formed into oxygen absorbent pouchesand bags but the bags did not have transparent areas. The bags withouttransparent areas are not desirable for many foods where the customerlikes to see the food. Therefore, the instant invention providessignificant advantages in a formation technique that results in lowercost and a much improved product design. With the invention bags andpouches no consideration need to be given to sachets being ingested withthe contents of the bag. Further, there is no concern about oxygenabsorbent labels coming detached and mixing with the contents of thebag. Further, as above stated, labels and sachets are not necessarythereby resulting in significant cost savings. By varying the width ofthe bands of oxygen absorber in the package forming sheet the amount ofoxygen absorption available may be matched to the particular productbeing packaged. This avoids waste of the oxygen absorber materialthereby lowering cost. These and other advantages will be apparent fromthe detailed description and drawings.

In FIG. 1 is shown an overhead view of a continuous banded film or sheet12 that has bands of transparent areas 14, 15, and 16. The sheet 12 alsohas bands of oxygen absorbing areas 18 and 20. As utilized hereincontinuous sheet or continuous film generally refers to a sheet that hasa length in a longitudinal direction greater than its width in thetransverse direction. In some application, the sheet or film may belonger than 1000 feet in the longitudinal direction. A typical length ofcontinuous sheets is between 5,000 and 10,000 feet for smaller packagingruns. Generally sheets of material for packaging have a preferred lengthof between about 5,000 and about 20,000 feet, for economical sheetformation, printing, and package formation with long runs. A continuoussheet or film is generally cut one or both of longitudinally andtransversely to form packaging blanks, which are used to form individualpackages. The invention is directed to both the continuous films and toindividual blanks for making packages, as will be described in moredetail below. When the term “oxygen absorbing band” is utilized in thisapplication it is intended to mean the longitudinal stripes formed bythe addition of oxygen absorber to a longitudinal portion of acontinuous sheet. It may also be used to refer to a portion of theoxygen absorbing band cut from the continuous sheet. In packageformation “stripe” may be used to identify a piece cut from thecontinuous band. Generally, the oxygen absorbing areas are nottransparent but are gray and translucent having the ability to passbetween 25 and 85% of visible light through the sheet. The areas betweenthe oxygen absorbing bands are generally transparent having an abilityto pass greater than 90% and preferably greater than 95% of the visiblelight applied to the transparent band.

In FIG. 2, a cross-section along line 2-2 of FIG. 1, there is shown athree layer structure including outer layers 27, 31 and an inner layer29. In this embodiment the inner layer 29 has oxygen absorbing portions24, 26 and transparent portions 28, 30, 32, to form the oxygen absorbingbands 18, 20, and the transparent bands 14, 15, 16 of the sheet 12. Theouter layers 27, 31 are applied to opposite faces of the inner layer 29to form the three layer structure. The outer layers 27, 31 preferablyare transparent and printable, as will be described in more detailbelow. In one embodiment, the three layers 27, 29, 31 are coextruded,but in still other embodiments two or more of the layers could belaminated after formation. Other techniques for forming multi-layerstructures will be appreciated by those having ordinary skill in the artand are within the scope of the invention.

The three layer structure of FIGS. 1 and 2 generally would be formedinto a sheet suitable for package formation by adhering the sheet 12 toa preformed oxygen barrier material such as a film that containsethylene vinyl alcohol (EVOH). FIG. 2A illustrates such a packagingsheet 40 having an EVOH sheet 34 attached to the sheet 12. The oxygenbarrier layer may be attached to the sheet 12 utilizing a tie layer 36which will allow secure attachment of the sheets of polyethylene andethylene vinyl alcohol to each other. Generally, the layer containingthe oxygen barrier material is shielded from the inside of the packageby an oxygen permeable layer, such as layer 31. Shielding the oxygenabsorber layer from the package contents prevents the contamination ofthe oxygen absorbent material, such as iron, by material in the packageand also contamination of food material in the package. The oxygenbarrier sheet 34 may be attached during formation of the banded sheetsuch that it is coextensive with the continuous banded film 12 to formpackaging sheet 40. The oxygen barrier sheet it will be understood maybe comprised of several layers of material that may provide propertiessuch as strength or printability in addition to oxygen barrierproperties.

In FIG. 3 is illustrated packaging film 50 which consists of thepackaging film 40 with printing 52 over the areas 24, 26 of thecontinuous packaging film that contain oxygen absorbent. The areas 66and 68 are transparent and will, after package formation, allow theconsumer to view the contents of the package. The areas of oxygenabsorbent will be translucent and after printing the color andtransparency of the film in the printed areas is not apparent to theobserver. The printing does not need to only coincide with the areasover the oxygen absorber and may extend into the transparent areas asnecessary to form a pleasing design for the package. The sheet 50 may,depending on its width, be cut into several pieces transversely andlongitudinally, and then folded to form packages. The film also could beutilized as a cover for the open top of a tray containing food ormedicine. It also could be used as a wrap for a pre-existing oxygenpermeable package that did not have oxygen barrier properties. In FIG.4, the package 60 is formed of half of packaging sheet 50 that has beencut on line 54 (in FIG. 3). The package is wrapped and sealed on thebackside in the known manner for bag formation, not shown, and thensealed at the top 62 and bottom 64 adhesively or by heat and pressure.

Illustrated in FIG. 5 is a bag 70 that has transparent areas 72, 74. Theprinting area 76 overlaps the oxygen barrier area 78 and also ontotransparent areas 82, 84, 86, and 88. This package utilizes a greaterarea for printing and provides smaller windows for observing theproduct.

Illustrated in FIG. 6 is a bag 90 that is provided with oxygen absorbingbands 92, 94. The transparent areas 96, 98, 102 are transparent. Thetransparent areas 98, 102 have been utilized for the seals 62, 64.Printing as been carried out in the entire packaging sheet used to formthe package except for window 104 where the product may be observed in acentral portion of the bag.

Any suitable oxygen scavenger may be utilized in the invention. Typicaloxygen scavengers are sulfur dioxide, chelates of salicylic acid or asalicylate salt. Other suitable oxygen scavenger materials are salts orchelates of metals such as zinc, copper, aluminum, and tin. Iron oxygenscavengers are preferred in many application because they are effectiveand low in cost.

A most preferred oxygen scavenger is reduced iron powder coated withactivating and acidifying materials. It preferably has 1-25 μm meanparticle size, more preferably 1-10 μm mean particle size and mostpreferably 2-5 μm mean particle size for rapid scavenging and good poreformation. The combination and relative fraction of activating andacidifying components coated onto the iron particles are selectedaccording to the teachings of U.S. Pat. No. 6,899,822, U.A. PatentApplication Nos. 2005/0205841 and 2007/0020456, incorporated herein byreference. The coating technique is preferably a dry coating asdescribed in the references above. The current invention may useiron-based powders with a mean particle size of 1-25 μm, where ironparticles are pre-coated with activating and oxidation reaction promoterparticles to form a homogeneous powder. The sheets or articles producedwith the finely dispersed oxygen scavenging particles advantageouslypossess high reactivity with oxygen. The oxygen scavenging particlesdisperse well throughout the bands where they are utilized. A preferredembodiment of the iron powder with activating and acidifying ingredientsis the dry coated oxygen scavenging particles as disclosed in U.S. Pat.No. 7,951,419 hereby incorporated by reference.

The polymer containing the oxygen scavenger may be any suitable polymerthat is permeable to oxygen and readily extruded. Suitable materialsinclude polyolefin such as high density and low density polyethylene andpolypropylene and modified forms thereof, polyester such as polyethyleneterephthalate, polyamide such as nylon 6 and nylon 66, ethylene-vinylalcohol copolymer, polyvinyl chloride, styrene-ethylene copolymers,polyester, polyurethane, and polyvinylindene chloride. A preferredmaterial is low density polyethylene as this material is transparent,low in cost, extrudable at relatively low temperatures, and transmitsoxygen.

Polymers utilized in the invention may also include biodegradablepolymers such as polylactic acid and its copolymers. Other biodegradablepolymers include polycaprolactone, thermoplastic starches, cellulose,and polysaccharides.

Packaging materials of the invention also preferably include an oxygenbarrier layer. The polymer forming the oxygen barrier layer may be anymaterial that will prevent the transmission of oxygen. Such materialsinclude metallic layers of tin or aluminum and polyvinyl alcohol. Apreferred material is ethyl vinyl alcohol (EVOH) as this material isreadily available, relatively low in cost, extrudable at polyethylenetemperatures, and has very good oxygen barrier properties.

The packaging films of the invention may be extruded as a continuousunitary packaging member with an oxygen barrier layer and layers withbands of oxygen absorbent. Alternatively a continuous oxygen absorberbanded extruded sheet may be formed and then laminated with separatelyformed oxygen barrier layer containing sheet by the use of suitable tielayers to adhesively connect the sheets. The packaging may be printed byprinting the barrier layer sheet prior to lamination. It is alsopossible to print the oxygen banded material after extrusion orlaminating.

The continuous packaging sheets of the invention with longitudinal bandsof oxygen absorber generally do not require any special packaging asthey are self protecting due to the many layers thickness of the roll.The rolls generally have a length of greater than 1,000 feet and themany layers, containing oxygen barrier layers, wrapped on the rollprovide protection from oxygen penetration. The rolls of the inventionmaterial may be handled as are the rolls of printed packaging materialnow utilized in the food and medical industry. Normally when thematerials are first fed off a roll this leader material is not utilizedas it is lost during setup. This top layer material would generally bethe only packaging material that might be affected by oxygen in storage.

The following are illustrations of packaging sheets of the invention. Ineach of the sheets illustrated where the oxygen absorber is indicatedthe oxygen absorber is in bands separated by bands of transparent lowdensity polyethylene that do not have oxygen absorber present. In allinstances the polyethylene is low density polyethylene. The coated ironoxygen absorber is an oxygen scavenger package prepared by coating ironparticulates, 4-5 μm mean particle size, with sodium bisulfate andsodium chloride to form a homogeneous coated composite powder having acomposition by weight of 80% iron, 10% sodium bisulfate, and 10% sodiumchloride.

A three layer coextruded sheet comprising

Polyethylene Polyethylene plus coated iron oxygen absorber in bandedareas Polyethylene

is laminated, with a tie layer, to a coextruded sheet comprising

Polyethylene Tie layer ethylene vinyl alcohol Tie layer Polyethylene

to form a packaging sheet with oxygen barrier properties and oxygenabsorbing properties

The sheet would be utilized with the layer comprising the oxygenabsorber on the inside of the sheet and printing on the outside of thesheet. The sheet containing the banded oxygen absorber would be about 3mils thick. The sheet with the oxygen barrier layer would be about 2mils thick.

Another illustration of the invention packaging material would be alaminate of a two layer coextruded sheet containing the banded oxygenabsorber laminated to a five layer structure containing an oxygenbarrier layer. The laminated structure would be:

polyethylene tie layer ethylene vinyl alcohol polymer tie layerPolyethylene polyethylene and coated iron oxygen absorber Polyethylene

The following illustration of invention is the layer structure of asingle step coextruded, oxygen absorber banded, packaging sheet.

Polyethylene tie layer ethylene vinyl alcohol polyethylene and coatediron oxygen absorber Polyethylene

The printing of the packaging films of the invention preferably iscarried out by unrolling the oxygen absorbent sheet and printing it byrotogravure or flexographic processes. This allows for printing brightcolors and dark colors on the sheet, particularly where the band ofoxygen absorber is present. It further would be possible that the oxygenbarrier sheet could be printed prior to its being attached to the bandedlayer of oxygen absorber sheet. It is also possible that the printing ofthe sheet could be carried out as it is unwound prior to being slit bothin the longitudinal and transverse direction to form the blanks fromwhich bags are made or the packaging materials are utilized as coveringsfor containers.

The amount of iron in the bands of oxygen absorber may be any amountthat provides the necessary result in a particular package. Typicallythe oxygen absorber portion of coated iron oxygen absorber is present inan amount of between 5 and 80% by weight of the polymer layer portioncontaining the oxygen absorber.

The polymer bags of the invention may be utilized for any package thatrequires a reduced oxygen atmosphere in the bag. Typical of suchmaterials are food materials such as coffee, fresh meat, beef jerky,pasta, baby food and other moist foods. The packages also may be usedfor medical products such as pills and replacement body parts whichrequire protection from oxygen. The oxygen absorber is activated bywater that comes from the materials packaged such as fresh meat or beefjerky.

The phrase “tie layer” as used in the description of packaging materialsof the invention refers to a thin layer utilized to join previouslyformed sheets in order to form them into laminate. It also refers tolayers extruded between dissimilar polymers in an extrusion head inorder to bind these polymers. Typical polymers or solvents utilized intie layers for coextrusion of a polyethylene layer to an ethylene vinylalcohol layer are maleic anhydride grafted polyethylene or polypropyleneethylene vinyl acetate and ethylene acrylic acid copolymers. Typicalpolymers utilized to join layers during coextrusion are commercialresins such as ADMER (Mitsui Chemical) maleic anhydride grafted resin,AMPLIFY (Dow Chemical) functionalized polyethylene and PLEXAR(LyondellBasell) maleic anhydride grafted polythylene. A preferred tielayer polymer for joining ethylene vinyl alcohol and polyethylene duringcoextrusion is maleic anhydride grafted polyethylene or polypropylenebecause they give strong bond between EVOH and polyethylene. Generally,the tie layer serves no function in the sheet except to join the layers.

Extrusion heads for extruding the polymer sheets of the invention areknown in the art. As is conventionally known, various feedblocks may beused in conjunction with extrusion heads to form desired co-extrudedmaterials. In the present invention, a feedblock receives the differentmaterials to be incorporated into a sheet of material and delivers thatmaterial to a die that forms the sheets. For instance it would be knownthat the bands containing oxygen absorber would need to be made with aresin of lower viscosity as the addition of the particulate iron oxygenabsorber would raise the viscosity. It is also known in the art toextrude polymer sheets in widths from only a few centimeters up to morethan two meters in width, depending upon the desired packaging. In someembodiments wide polymer sheets are extruded that will be slit bothlongitudinally and transversely to form blanks for use in formingpackages.

A feedblock is illustrated in FIG. 7. There, a feedblock 110 includesthree openings 112, 114, 116 laterally spaced by spacers 122, 124 andbounded above and below by a top 140 and a bottom 142. In use, theoxygen absorber-containing composition is extruded through opening 114and the transparent polymers are co-extruded through the openings 112,116 to form a sheet containing an oxygen-absorbing strip 130 locatedtransversely between two transparent strips 134, 136, such as shown inFIG. 7A. FIGS. 7 and 7A are not to scale.

FIG. 8 shows an alternative feedblock 110, substantially identical tothat of FIG. 7, except it includes additional openings 118, 120, andspacers 126, 128. An extrusion head employing this feedblock results ina film such as shown in FIG. 8A having three transparent strips 134,136, 138 and two oxygen-absorbing strips 130, 132, which is similar tothe film illustrated in FIGS. 1-3. As noted above, outer layers, such asthose designated as reference numerals 27 and 31 in FIGS. 2 and 2A maybe co-extruded with the striped layer, or may be laminated afterextrusion.

Although the inventor has used feedblocks such as those illustrated inFIGS. 7 and 8, he has found that because of viscosity differencesbetween the transparent polymers and the oxygen-absorbent material thatopenings having the same height “h” as those shown in those figuresresult in a film having a non-uniform thickness. Specifically, theillustrated feedblocks 110 result in thicker oxygen-absorbing stripsthan transparent areas. An observed cross-section of a film formed usinga head 110 of FIG. 7 is illustrated in FIG. 9. As shown, the center ofthe oxygen-absorbing strip 130 is thicker in the middle, and narrows atthe junction with each of the transparent strips 134, 136, which in turnnarrow further out to their edges. In one application, the film was asthick as 3.5 mil at the center and as narrow as 2 mil nearer the edges.This difference is extremely noticeable upon winding several thousandfeet of the film on a roll.

A preferred feedblock 210 is illustrated in FIG. 10. The feedblock 210is substantially identical to that illustrated in FIG. 7, except top 240and bottom 242 are arcuate instead of planar. Accordingly, the height ofcentral opening 214 varies along the transverse direction, i.e., betweenopenings 212, 216. The respsective heights of openings 212, 216 alsovary with width, being larger at the edges of the feedblock 210. The arcof the top and bottom may be calculated to ensure a substantiallyuniform thickness across the film, based on the materials (and theirviscosities) to be extruded. Thus, a different head is used for eachcombination of extruded materials.

In another embodiment, the height of the openings, i.e., the distancesbetween the top and bottom are adjustable. Such an adjustable feedblock310 is illustrated in FIG. 11. There, the top 340 and the bottom 342 aredeformable upon application of a force along arrows F1 and F2,respectively. As illustrated, both the top and bottom are fixed atlateral ends and deformed to contact spacers 322, 324, creating anarcuate shape above and below the openings 312, 314, 316. The spacersmay be sized for the application, that is, such that sufficient force isprovided to result in contact of the spacers by the top and bottom.Alternatively, the spacers may also be deformable under the forces F1and F2. In an application in which more openings are provided, it may bedesirable to provide additional forces on any openings that will passthe oxygen-absorbing material therethrough. The forces may be appliedusing any known methodologies, although the force is preferablycontrollable by the user to fine-tune the size of the opening. In oneexample, set screws may be provided outside the extrusion head that areselectively turned to apply a desired force. Other arrangements will beappreciated by those of ordinary skill in the art.

In an embodiment similar to that of FIG. 11, the deformable top andbottom may be fixed to the spacers, such that a force applied alongarrows F1 and F2 will only create a curvature in the central opening314.

Although only oxygen absorber has been discussed as an additive to thebands, it is possible to utilize other additive with the iron particles,in the inner layer of the packaging sheet or other layers. Additivessuch as biocides and fungicides could be combined with the polymer ofthese or other layers. Brighteners could be added to the layers or tothe printing layers. Colorants also could be used to give thetransparent areas a color or tint to improve the look of the product inthe bag or pouch.

The following examples are illustrative and not exhaustive of theinvention. Parts and percentages are by weight unless otherwiseindicated.

EXAMPLE 1

A film is formed comprising three layers of: low-density polyethylene/polyethylene (70%)+ reduced iron coated with activating and acidifyingmaterial (30%)/low-density polyethylene to make a 3 to 4 mil thick filmwith a width of 9 inch. The coated iron is about 12 to 18% by weightwith respect to the film if it were spreading across the width of thefilm. The coated iron is located in the middle layer of the band whichis centered in the film and is approximately 4 inch wide. The net coatediron content in film can be approximated by multiplying the feed contentby the ratio of the band width with respect to the full width of thefilm. The oxygen scavenging performance of the band film was tested byusing a pouch test method. Sample films were heat laminated onto a highgas barrier clear PET substrate. The laminated film and the substrateswere heat sealed to form a 7″×7″ pouch with the 4 inch band portionlocated in the middle of the pouch with approximately 1.5 inch clearwindow on each side of the band. The net coated iron content asdetermined by the ratio of the band width with respect to the pouchwidth was 6.86 and 10.29%. Ten grams of moisture regulator made ofsilica gel granules and water with a water activity of 0.85 was sealedin Tyvek bag and put in the pouch prior to the final seal of the pouch.The bag was injected with 300 cc of O₂/N₂ mixture to achieve a startingoxygen level of approximately 4-4.5%. The oxygen absorption rate wasmeasured using a MOCON PacCheck Model 450 Head Space Analyzer at varioustimes at room temperature. The oxygen absorbed by the samples at thesetimes is shown in Table-1. The data demonstrated that both the high andlower contents of the coated iron extruded in films in band form provideoxygen scavenging performance. The concentration of oxygen in the pouchdecreased rapidly with time.

TABLE 1 Oxygen absorption of the band films containing coated iron FilmCoated iron Pouch gauge content in pouch O2 Absorption Test sample mil %time, hrs O2 conc, % 1 4 6.86 0 4.25 24 2.85 72 0.336 2 3.5 10.29 0 4.3824 2.254 72 0.0236

This example demonstrated that the band film containing coated iron canbe used to make printed food bags as a sealant film. An example can bethat a polyethylene terephthalate (PET) printed polyethyleneterephthalate barrier film multilayer substrate of 1.5 mil that isprinted except that it contains a 4″×2″ not printed clear window isformed every 8 inches. The multilayer printed substrate has thestructure: PET/print/adhesive/PET. The multilayer substrate is thelaminated onto the oxygen scavenger containing film. Blanks forpackaging each containing a window are cut from the laminated sheet andfolded to make bags that have a clear window such as in FIG. 6. The bagis utilized for beef jerky packaging. After two weeks the bag is testedand found to have an oxygen level of less than 0.2% as compared to aninitial oxygen level of 5% at the time of packaging.

EXAMPLE 2

The bag of example 1 is compared with a conventional beef jerky packagethat has a label containing oxygen scavenger. The package materialhaving the banded oxygen absorber in the continuous sheet was found tobe as effective as the oxygen absorbing labels conventionally used onthe inside of the package.

1. A packaging material comprising a layer having a longitudinal band ofoxygen absorber and a longitudinal band substantially free from oxygenabsorber transversely adjacent to the longitudinal band in the layer. 2.The packaging material of claim 1 wherein the longitudinal band issubstantially transparent.
 3. The packaging material of claim 1 whereinthe band of oxygen absorber comprises electrolyte adhered to ironparticles as the oxygen absorber.
 4. The packaging material of claim 1wherein the layer comprises a first layer and said packaging materialcomprises one or more additional layers.
 5. The packaging material ofclaim 4 wherein one of the additional layers comprises an oxygen barrierlayer.
 6. The packaging material of claim 5 wherein the oxygen barrierlayer comprises a material selected from the group consisting ofpolyethylene terephthalate, polyvinylidene chloride (PVDC), ethylenevinyl alcohol copolymer (EVOH), nylon, and polyvinyl alcohol.
 7. Thepackaging material of claim 4 wherein the layer or one of the one ormore additional layers comprises polyethylene.
 8. The packaging materialof claim 7 wherein a the oxygen absorber is disposed in the layercomprising polyethylene.
 9. The packaging material of claim 8 whereinthe layer comprising the polyethylene and the oxygen absorber is in aninner layer of the packaging material.
 10. The packaging material ofclaim 1 further comprising printing over at least a portion of the bandof oxygen absorber.
 11. An enclosure formed utilizing a package formingblank taken from a packaging material, the packaging materialcomprising: a first layer; and polymer a second layer adjacent to thefirst layer and comprising a longitudinal band containing an oxygenabsorber and a longitudinal band substantially free from oxygen absorbertransversely adjacent to the longitudinal band in the second layer. 12.The enclosure of claim 11 wherein the packaging material comprises acontinuous sheet and the package forming blank is a section takentransverse of the longitudinal direction of the continuous sheet. 13.The enclosure of claim 11 further comprising printing over at least aportion of the band containing the oxygen absorber.
 14. The enclosure ofclaim 11, wherein the band free from oxygen absorber is substantiallytransparent.
 15. The enclosure of claim 11 wherein the enclosure definesan internal volume and the second layer is arranged to be incommunication with oxygen in the internal volume. 16.-19. (canceled) 20.A polymer bag comprising a polymer layer, the polymer layer comprising astripe of oxygen absorber embedded in the polymer of bag and atransparent stripe free from oxygen absorber transversely adjacent tothe stripe of oxygen absorber embedded in polymer area, the transparentstripe being substantially free from oxygen absorber is not present. 21.The polymer bag of claim 20, further comprising printing over the areacorresponding to the stripe of oxygen absorber.
 22. The polymer bag ofclaim 21 wherein the entire area corresponding to the oxygen absorber isprinted.
 23. The polymer bag of 21 wherein at least a portion of an areacorresponding to the transparent stripe is not printed so as to allowviewing of contents in the package.
 24. The polymer bag of claim 20wherein the bag has a rear portion that contains the overlapping areasof the polymer sheet forming the bag and the bag is sealed at the ends.25. (canceled)